Rich people might have more money than the rest of us, but it turns out, they also have more of something less enviable: uninvited guests. According to a recent study in the journal Biology Letters, wealthier homes are host to more bug species than lower income homes. That is, while higher-income homes may or may not have more insects, spiders, and mites infesting their nooks and crannies than lower-income homes overall, they definitely have a greater diversity of bug species. 

A few months ago, we reported on an urban biodiversity study that found that homes in Raleigh, North Carolina were host to a vast range of arthropod species (insects, arachnids, and other animals with exoskeletons, segmented bodies, and jointed legs), including book lice, ants, cobweb spiders, midges, and leafhoppers. For the current study, the same team of researchers delved deeper into that data, which sampled 50 homes across Raleigh, to analyze the link between affluence and arthropod diversity. 

Researchers found that, on average, homes contained 61 different arthropod species. But there were distinct differences between higher- and lower-income homes. While wealthier homes had an average of 100 different species of arthropod, less wealthy homes had an average of 50.

Researchers aren’t exactly sure why wealthy homes have a greater diversity of arthropod species, but they believe it may be part of a broader phenomenon they call the “luxury effect,” in which greater biodiversity is found in higher income areas. National Geographic explains that earlier studies have found that higher-income areas also have a higher diversity of vegetation, and researchers believe the higher diversity of arthropods may be linked to the larger yards and more diverse plant life in wealthier neighborhoods.

“Our finding, that homes in wealthier neighborhoods host higher indoor arthropod diversity (consisting of primarily non-pest species), shows that the luxury effect can extend to the indoor environment,” the study explains. “[It] suggests that the management of neighborhoods and cities can have effects on biodiversity that can extend from trees and birds all the way to the arthropod life in bedrooms and basements.”

[h/t National Geographic]

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